As is widely known, a perpendicular magnetic recording head has a main pole layer and an auxiliary magnetic pole layer (return yoke layer) which are laminated with a nonmagnetic insulating layer therebetween in a surface that faces a recording medium. Coil layers apply a recording magnetic field to the main pole layer and the auxiliary magnetic pole layer.
The area of the main pole layer exposed to the surface that faces the recording medium is sufficiently smaller than the area of thee auxiliary magnetic pole layer. The main pole layer and the auxiliary magnetic pole layer are magnetically connected to each other on a deep side in the height direction. When the coil layers are energized, a recording magnetic field is induced between the main pole layer and the auxiliary magnetic pole layer, and this recording magnetic field perpendicularly enters a hard film of the recording medium from a leading face exposed to the medium-facing surface of the main pole layer, and returns to the auxiliary magnetic pole layer through a soft film of the recording medium. Accordingly, magnetic recording is performed in the portion of the recording medium that faces the main pole layer.
In a perpendicular magnetic recording head as described above, in order to improve recording density and prevent fringing at the time of skewing, the main pole layer that is formed on the nonmagnetic insulating layer has a shape, as viewed from the surface that faces the recording medium, that is a trapezoidal shape (bevel shape) which becomes narrow on the side of the nonmagnetic insulating layer.
In the related art, as described in, for example, Japanese Unexamined Patent Application Publication No. 2004-079081 (corresponding to US Pub. No. 2004032692 A1), side milling is performed on a side face of a main pole layer after the main pole layer is formed on a nonmagnetic insulating layer using a frame plating method, thereby forming a trapezoidal main pole layer which becomes narrow on the side of the nonmagnetic insulating layer.
Recently, narrowing of a track is advanced so that it can be adapted to higher recording density. As described above, since the main pole layer is formed in inverted trapezoidal shape, when the recording track width is reduced, the width of a bottom part (on the side of the nonmagnetic insulating layer) of the main pole layer is reduced to be smaller than the recording track width. If the width of the bottom part of the main pole layer S becomes extremely small, the bottom part of the main pole layer often floats or the bottom part is often peeled off, during the manufacturing process. In a state where the main pole layer is unstable, the recording characteristics are degraded and the quality of a magnetic head deteriorates.